Indian Railways — theft my luggage

Respected sir i am the residence of chandigarh.in 10/05/2018 i travelled train no 04973 in coach no s7 from chapra to ambala cantt. When train is come around at 9:30 pm in platform no 2 and when we enter into the train there was some people in my seat i say to that you are in my seat please leave my seat but they fight with him and unfortunately my luggage is theft. I complaint to chapra grp plaese sir help me in my luggage their was around 15 lakh jewellery and some important document and one cheque book of obc bank and 1 atm of hdfc bank sir my mobile no is [protected]